Hi, so I'm new to Canons L series and I've just rented one out of necessity because another lens of mine is being fixed. I'm using the 24mm f1.4 II on my 7D. My problem is that I have it stopped wide open and my images are turning out really dark. The only time I can really see anything is when I bump the ISO pretty high. I'm used to using lenses with a wide aperture, my other two being a 1.4 and a 1.8, and I've never had this issue. Any ideas?